Photoresist developer reclamation technology and system

Abstract

A tetramethylammonium hydroxide (TMAH) generally used as photoresist developer for manufacturing LSIs and LCDs is recovered from developer waste (spent developer) using an electrodialysis (ED) method, and purified by ion exchange (IE) technologies. Reclaimed developer features analytically the same purity as commercial fresh one. This reclamation system can achieve a stably high TMAH recovery rate of more than 80%. Furthermore, it has the great advantages of saving operating costs, which amounts to 66.2% (for LSI) and 78.3% (for LCD) total cost reduction compared with conventional no reclamation system in a case study, as well as reducing environmental load.